Method of making steel castings in permanent molds



H, 19%.. J. W. BE'TI'TENIDWF METHOD OF MAKING STEEL CASTING'S IN PERMANENT MOLDS 5 Sheets-Sheet Filed May 12, 192

ll nll INVENTOR J. W. Bofiendorf,

BY .4 1 Q ATTORN EYS Feb. 11, 1.930. w, BETTENDORF 1,746,300

METHOD OF MAKING STEEL'CASTINGS IN rnmwwn'r HOLDS 5 Sheets-Sheet 2 Filed May 12. 1926 i INVENTOR. J W Beflandorf,

hm a.

ATTORNEYS.

Feb. 11, 1930.

J. W. BETTENDORF METHOD OF MAKING STEEL CASTINGS IN PERIANENT HOLDS Filed May 12, 1926 5 Sheets-$heet 5 INVENTOR J. W :Bcflendo rf,

BY am O'MQ Ma ATTORNEYS Feb. 11, 1930. 1,746,300

METHOD OF MAKING STEEL CASTINGS IN' PERMANENT HOLDS J. W. BETTENDORF Filed May 12, 1926 5 Sheets-Sheet 4 INVENTOR iwgefiendorf,

ATTORNEYS Feb. 11, 1930. w, BETTENDORF v 1,746,300

METHOD OF MAKING STEEL CASTINGS IN PERIAQENT HOLDS Filed May 12, 1926 5 Sheets-Sheet 5 INVENTOR lw eflendorf,

BY aw. 4N1 1M4 ATTO R N EYS Patented Feb. -11, 1930 PATENT OFFICE JosErnw. nn'r'rnnnonr, or nnr'rnnnonr, IOWA.

METHOD' OF MAKING STEEL CASTINGS PERMANENT HOLDS Application filed May 12,

This invention relates 'to the manufacture of relatively large steel castings, such as railroad'car side frames, and more particularly to the method, of making such castings.

Heretofore railroad car truck side frames had been cast in sand molds having baked and green sand cores. The surface of the resulting castings has ordinarily been quite rough and has been impregnated with particles of burnt sand. Fins and other surface irregularities have alsooccurred as a result of the useof sand molds. To prepare such castings for use in railroad cars it has been found necessary to sand blast the surface generally, and to chip off the surface irregularities, fins, etc. Furthermore, it has been necessary to chip those portions of the casting which must be of relatively accurate dimensions, such as, for example, the seats for springs, bolsters and bearings. It may be noted that such surface finishing has been relatively expensive and has necessarily decreased the rate of production of'the castings. It is'an object of my invention to east side frames and other intricate large steel castings in a metal mold of such construction y to prevent cracking or injuring the metal that the metal of the mold will contact with the exterior of the casting. to form smooth external surfacesand yet permit the necessary shrinkage of all parts'of the castings thereof.

Another object of this invention is to provide a method of casting relatively large steel objects with smooth and accurate surfaces whereby no cleaning or chipping of said surfaces will be required beforeputting said articles in use.

A further object of the invention is to pro-' vide a method of casting railroad car side frames so that portions 'thereofwill be smooth andaccurate. and so that said-side frames may be employedxin cooperativerrelation with other portions of railroad. car trucks with a minimum 'of'preparation. of the cast surfaceof said side frames;

It is also an object of my invention to cast against metal members-those portions of the inner surfacesof a side frame casting which need to be of accurate dimension to form 1926. Serial No. 108,559.

Fig. 3 is a plan view of the drag with the sand cores and casting metal in horizontal section.

Fig. 4 is a vertical longitudinal section through the mold with the sand cores in position, the left half of the cope being omitted.

Fig. 5 is a view similar to Fig. 4, with the cope in place and the casting also shown in section.

Fig. 6 is a longitudinal section through a journal box.

and central core member.

Fig. 8 is a fragmentary longitudinal section through the gate.

Fig. 9 is a fransverse'section through the portion of the mold in which a brake hanger is cast.

Fig. 7 is a transverse view through the gate Fig. 10 is a longitudinal'section through hanger is cast.

Fig. 11. is a perspective view of the sand cores assembled for one-halfof the main body of the casting. I

Fig. 12 is a perspective view of a casting formed in the mold. w

Fig. 13 is a plan 'of amodified form of core-for forming the window or large opening in the casting.

Fig. 14 'is, an elevation ofthe core structure shown in Fig. 13. Aform of mold contemplated b my in.-

vention is shown generally in the rawjiugs.

the portion of the mold in which a brake The mold as shown is particularly adapted ",for .the casting of a railroaod truck side frame 1 which is substantially similar to that shown in Patent 1,351,326 of C; J. W. 'Clasen, granted August 31, 1920. The casting 1 comprises top and bottom members 2 and 3 and column members 4 extending between the members 2' and At each end of the casting are integral journal boxes 5 and- 6 and on one side of the casting are provided brake hanger brackets? and 8. The members 2, 3 and 4 define a bolster opening having a top 9, side members 10 and a bottom portion 11 forming a spring seat. The said bolster opening is adapted to receive the bolster and the springs on whichthe bolster is mounted, as is well known in railroad car construction.

The mold comprises a cope member C and a dra member D, which members may be parte in a median plane ofthe casting as shown in the drawings, or near one edge of the casting 1. After assembly, the mold members may be maintained in assesmbled which form the inwardly facing portions of the exterior of the journal box, must be mounted to moveinwardly so that they will permit shrinkage of the journal box portions of the casting toward the center thereof. Thus the said portions 13 and 14 may be moved toward the center of the mold after the solidification of said casting and before the com lete shrinkage'thereof, as particularly in icated in Figs. 4 and 5, to permit further shrinkage of the casting upon cooling, and consequent moving of the journal boxes toward the center of the casting; The

members 13 and 14 are shown as individually moved by similar cam mechanisms. The cope and drag each carry pairs of fixed sup orts, 15 and 16 respectively, and each pair 0 supports carries a cam shaft 17 provided with cam fingers 18, The movable portions 13 and 14 of the cope and drag carry projections having cam apertures in which'thecam fingers may rotate. The ends ofthe cam shaft are preferably made square so that they may receive means such as a crank to rotate the shafts, and these shifts may be rotated either manually or mechanically. The portions 13 and'14 of the mold membersC and D are provided \with cooperative inclined surfaces 13 and '14 so that the 'saidportions 13 and 14 are moved upwardl'y and downwardly respectivelyand at an angle, and thus the.

casgi ng is free to shrink toward the center. In i 5 the members 13 and 14 at the left side 6 the figureare shown in molding position while at the right side of the figure they are shown moved away to permit shrinkage of the casting.

In order to accurately form portions of the inner faces 10 of the column members 4, which define the sides of the bolster opening and to form the inner face 9 of the top member 2 so that they will be smooth and accurate in size, I have provided a plurality of collapsible metal core portions which are readily movable inwardly to permit shrink-' age of the casting upon solidification and cooling. A preferred form of mounting this core, so that the portions may be easily and quickly moved inwardly after the casting has been poured, is to have them so connected as to be movable by any, suitable common.

.top member and overlies t-hg end portions of the core members 25. The core members and 26 are provided with inwardly extending I lugs 27 having pins 28 transversely mounted therein. Mounted in the cope .and drag is a rotatable shaft 29 having-a pair of disc mem- I bers 30 carried thereby for rotation with the shaft. The disc members 30 are provided with cam slots 31 in which the ends of the pins 28 are carried.v Upon rotation of the shaft 29 the metal cores are moved inwardly by the engagement of the ends of the pins 28 in the cam slots 31. The cam slots are preferably so designed that the core member 26 will initially'move inwardly at a greater speed than the core members 25, so that there will be no interference between the core members. Preferably the core member 26 is provided with guides 26" to engage the discs 30 so that said member 26 will move inwardly uniformly and without binding. It will be thus seen that the said core member 26 is movable inwardly simultaneously by common operating means to permit shrinkage of the casting. Preferably the core members 25 not only form the inner faces 10 and 9, respectively, but are channel-shaped in cross section so that they extend over'and form part of the outer faces of the column members 4.

The journal box cores 35 are preferably multi-part sand cores, comprising bottom members and top members. Metal inserts 36 may be disposed between said bottom and top members to receive threaded ends of handles 37, said handles being advantageous in positioning said top members within the mold. The bottom members may-cooperate with apertures in the adjacent drag member to properly position said bottom members and likewise said metal inserts may be provided with projections cooperating with depressions in said bottom and top members, whereby said inserts and top members may be properly positioned within the mold.

opposed cores 38 form the opposed portions of the top and bottom members 2 and 3. Upon both faces of the cores 38 are the core members 42 which form the triangularlyshaped openings in the side frame. If desired for purposes of ejection of the casting the metallic members 43 may be incorporated in the core members 42. If it be desired to obtain smooth and more accurate inside surfaces of the channel members forming the triangular shaped openings, this may be accomplished by incorporating the metal'memhers 44 in the cores 42 as shown in Figs. 13

and 14.

It is also obvious that other of the core members disclosed herein may be formed, if

desired, of metal members with suificient sand portions intervening to permit the proper shrinking of the casting by crushing the sand cores.

Where it is desired tocast brake-hanger supports integral with the side frame, the necessary mold cavity and core forming parts may be disposed within the auxiliary mold portions 45 through a side aperture which may be closed bylthe doors 46.

In order to form a smooth and accurate spring seat 11 a metal slab core 4'? is prober 47 and engage shouldered recesses in the member 51, as shown in Fig. 1. By this construction the gate is rigidly held in place and a suitable projecting pouring cup may be used ifdesired. I

Underlying the members 51, 52 are'sand core members 57, 5,8 which are provided with extensions 59, which extensions project into recesses in the mold so that the incoming molten metal will. flow in streams along the passageway and will not have to flow across the metal of the mold until after its flow has been retarded somewhat.' By this means the mold is prevented from being overheated or melted due to the engagement with the more rapidly flowing molten metal.

i It will. thus be seen that the incoming molten metal will flow over substantially level sand'cores and does not come in contact with the metal mold until thestream has been divided and the direction of How of each branch changed so that any tendency of hot metal to overheat or wear away the mold is reduced to a minimum.

It will therefore be seen that I have provideda relatively simple method for molding substantially all of the exterior surfaces of a relatively large, intricate steel casting, and that I have accomplished this with a metal mold which is'relatively exceptionally light a for metal molds for steel castings.

It will be seen that in the embodiment of my invention herein described themass of the mold, and hence the chilling capacity thereof, is relatively small.

greater than the weight of the casting. In

previous permanent metal molds for the cast- Thus in the present moldthe weight thereof is not much ing of steel articles the weight of the mold a has ordinarily been several times heavier than the article to be cast therein. In the mold herein described, however, the time between pouring is ordinarily, suflicient to permit the mold to substantialy cool off, and hence I have found the use of a bulky mass of metal mold of large chilling capacity unnecessary.

It will thus be seen, therefore, thatby pro- 'viding suflicient chilling capacity I have produceda method of making a relatively large metal casting. having a fine grain, homogeneous, non-porous structure, and have prevented deterioartion of the mold by so chill ing it as to prevent melting of the mold wall due to the high metal. v It will also be seen that I have provided temperature of the casting a relatively simple method forforming the i exterior surfaces of the casting'and yet have made adequate provision for permitting those parts of the mold which form parts of the exterior surfaces of the casting which face,

inwardly, that is, toward the center of the casting, also to move inwardly'or be moved inwardly sufficiently to permit contraction of the casting toward its center, dueto shrinkage and cooling of the molten metal. To hose skilled in'the art many modifica tions of and widely differing embodiments and applications of my invention will suggest themselves, without departing from the spirit and scope thereof. My disclosures and the descriptions herein are urely illustrative and are limiting.

What I claim is:

1. The method of casting a car truck steel side-frame having members forming a centrally disposedbolster opening and having outwardly projecting integral journal boxes adjacent the ends of the frame, which method comprises introducing molten metal of the denot intended to e in any sense sired characteristics into a separable metal mold having a mold cavity of the desired shape and, after the metal has set, moving inwardly the portions of the metal walls of the mold which form those outer surfaces of the journal boxes which face inwardly toward -the bolster opening, and also moving inwardly metal core members forming the inward- 1y facing interior surfaces of the bolster open- 10 ing topermit ishrinka e of the portion of thecasting defining sai bolster opening, and opening the mold and removing the casting. 2. The method of casting a car truck steel side frame having members forming a cen- 5 trally disposed bolster opening and having integral laterally extending portions, which method comprises introducing molten metal of the desired characteristics into a separable metal mold having a mold cavity of the go desired shape, and, after the metal has set, releasing the mold members contacting with the inwardly facing outer surfaces of saidla'terally projecting side frame portions to permit said portions to shrink freely toward each 35 other without restraint, and also moving inwardly core members forming inwardly facing interior surfaces of the bolster opening to permit shrinkage of the portion of the casting defining said bolster opening, and

3') opening the mold and removing the casting.

In testimony whereof I aflix my signature.

JOSEPH W. BETTENDORF. 

